Roof insulation



H. S. WOOD May 14, 195% ROOF INSULATION Filed Dec.

I /5 Inventor fllmom 8. M 0

Attorneys United States Patent 3,382,638 ROOF INSULATION Harold S. Wood, 13 Dundela Park, Dublin, Sandycove, Ireland Filed Dec. 3, 1965, Ser. No. 511,420 1 Claim. (Cl. 52-495) ABSTRACT OF THE DISCLOSURE Roof construction comprises an elongated metal roofsupporting member having a web and a flange, and a pair of strips of expanded polystyrene insulation disposed on opposite sides of the web and flange and encompassing the flange on all sides with the strips contacting each other along the side of the flange opposite the web. The strips have tongue-and-groove connection with each other, and insulating sheets are dovetailed into the strips on opposite sides of the metal member.

This invention concerns the insulation of roofs of the kind in which the roof proper is supported with the aid of metal members, purlins, rafters and the like. In order to provide satisfactory insulation against escape of heat through the roof of -a building or ingress of undesired heat or cold from outside into the interior of the building, it is necessary to insulate not only the roof covering, but also the metal members by which it is supported. The object of the invention is to provide a ready method and means for insulating a roof and the purlins or other metal members by which it is supported.

The invention provides a method of insulating a roof of the kind referred to which consists in applying to the lower side of the rafters or other metal members of the roof structure, shaped strips of expanded polystyrene, and fitting sheets of expanded polystyrene between the strips which are so applied to parallel members of the roof structure and are shaped to provide grooves or ledges to support the edges of said sheets. By this means a layer of expanded polystyrene is provided extending laterally beneath the roof surface and its metal supporting members.

Advantageously the strips of expanded polystyrene provided according to the invention are substantially I-shaped in cross-section, each having a deep narrow longitudinal groove to receive the projecting web or flange of a roof supporting member and a lateral groove to receive the marginal portion-s of a sheet of expanded polystyrene which extends laterally therefrom.

In order that the invention may be clearly understood and readily carried into practice it is hereinafter described with reference to the accompanying drawings which show by way of example a number of constructions adapted to different forms of the metal roof-supporting members, and wherein:

FIG. 1 shows in cross-section a form of expanded poly styrene strip according to the invention as applied to a roof-supporting member of L-shaped or T-shaped crosssection,

FIG. 2 is .a side elevation of the construction shown in FIG. 1,

FIG. 3 shows the cross-section of a transverse joint between the adjacent expanded polystyrene sheets,

FIG. 4 shows in cross-section one method of applying the expanded polystyrene strip shown in FIG. 1 to a roofsupporting member of Z or I] shape, and

FIG. 5 shows in cross-section a modified shape which 'the expanded polystyrene strip according to the invention may take when applied to a roof-supporting member of I-shaped cross-section and corresponding parts are indicated by similar reference numerals in all the viewss 3,382,638 Patented May 14, 1968 Referring to the drawings, FIGS. 1 and 2 show in full lines a rafter or the like 1 of L-shaped cross-section to the depending flange 2 of which a strip of expanded polystyrene 3 moulded to a substantially L-shaped cross-section and having a deep narrow groove 4 extending from the middle of the upper flange and mediately within the web portion of the strip. The bottom flange of the strip 3 is of very substantial thickness at the centre, but tapers towards the sides; this aflords ample insulation in the region below the groove 4 and at the same time gives the strip a neat appearance. The strip 1 is shaped so as to provide longiutdinally extending grooves 6, 6 on opposite sides thereof.

In applying the strip 3 to the depending flange 2 of the roof-supporting member 1 an adhesive is applied beneath the top flange of the member 1 and to both sides of the flange 2 and the strip 3 is then pressed upwards so that the flange 2 enters the groove 4 of the strip. The width of the groove 4 is preferably slightly less than the thickness of the flange 2 so that when pressed into position the strip 1 exerts a slight lateral pressure on opposite sides of the flange 2. A very firm bond between the strip 1 and the flange 2 is thus ensured when the adhesive sets.

It will be evident that the strip of expanded polystyrene applied so as to cover the underside of the roof supporting member 2 as above decsribed will afford a very effective insulation barrier protecting said member from the effect of hot air rising from below said member which would otherwise lead to condensation upon the metal member. In order to shield the roof surface completely sheets 7 of expanded polystyrene are mounted so as to extend from one roof member 1 to the next adjacent member parallel thereto, the lateral edges of the sheets 7 being fitted into the grooves 6. Several such sheets disposed contiguously in the same plane may be required in order to cover completely the space between. two adjacent parallel members 1, and in such case it is preferable to join the transverse edges of adjacent sheets where they meet. A tongue and groove connection such as is shown in FIG. 3 is advantageous for this purpose, but junction pieces of H-shaped cross section could also be used for this purpose.

If the metal roof-supporting member is of T-shaped cross-section the strips 3 may be applied thereto in precisely the same manner as is described above. Such a T-shaped member is indicated diagrammatically by the aid of the broken lines 8 and it will be readily seen that the underside of the member is fully protected by the strip 3.

The metal roof-supporting members sometimes have forms other than L- or T-shaped and the cross-sectional form of the strip may then need to be modified in order to enable the strip to be applied to the underside of the strip, or alternatively the strip may have an additional flange secured to it to carry the strip. Such a construction is shown in FIG. 4, wherein a dependent flange 9 is rivetted to the web of the Z-shaped member 10. The strip 1 is secured to the member 10 in the same manner as the strip 3 shown in FIG. 1 is secured to the depending flange 2. A similar construction may advantageously be adopted if the roof supporting member in question is of [l-shaped cross-section, for example as indicated by the broken lines 12 in FIG. 4.

If the roof-supporting member requiring to be insulated is of I-shaped cross-section it may be advantageous to apply separate strips of expanded polystyrene to the lower flanges thereof, as shown for example in FIG. 5, the strips together sealing the member from rising heat. A strip 13 of expanded polystyrene is moulded to shape and formed with a deep narrow groove 14 adapted to receive one of the lower flanges 15 of the I-member l1, and is .9 also formed with a longitudinal groove to receive the edge portion of a sheet of expanded polystyrene. A similar strip 13 of expanded polystyrene is applied to the other lower flange 15 of the I-rnember, and the two strips abut below the member. They are preferably secured to said member by an adhesive, although the adhesive may be superfluous with this construction. If desired the abutting surfaces of the strips 13, 13 may interfit with a tongue and groove connection, as-indicated by broken lines 16 in FIG. 5. The application of the invention to roofs of the kind referred to in which the roof covering is supported by metal frame members of any other cross-sectional form than angle, channel, T-shaped or Z-shaped will pressent no diificulty in view of the examples described above with reference to the accompanying drawings.

The invention thus provides a method and means whereby the whole of the underside of the roof may be covered with the highly insulating expanded polystyrenes, without leaving any crevices through which hot air may pass.

It may also be advantageous not only to apply the invention to the protection of the rafters and root surface, but to the roof principals or truss members. These may be covered by sheets of expanded polystyrene, the longitudinal edges of which are engaged in longitudinal grooves formed laterally in strips of expanded polystyrene such as above described suitably grooved to fit the edges of the flanges of the lower horizontal members and/ or inclined members of the roof principals to which they are firmly secured when so applied in position by the aid of adhesives.

By this means a roof, particularly a pitched roof may be completely protected on the interior surface thereof by expanded polystyrene of any desired thickness, and a very high degree of heat insulation is thus afforded. A roof thus protected has a very attractive appearance, while the additional weight imposed on the roof by the addition of the insulating material is negligible.

1 claim:

1. Roof construction comprising an elongated metal roof-supporting member having a web and a flange, a pair of strips of expanded plastic insulating material disposed on opposite sides of the web and flange and encompassing the flange on all sides, said strips contacting each other along the side of the flange opposite the web and having tongue-and-groove connection with each other in the region in which they contact each other, and sheets of insulating material having edges disposed in grooves in said strips and having a thickness substantially greater than the thickness of either of said web and flange, said web and flange being perpendicular to each other and said sheets being substantially coplanar with said flange.

References Cited UNITED STATES PATENTS 2,226,248 12/1940 Lunken 52-464 XR 2,526,116 10/1950 Browne 52-496 XR 2,438,140 3/1948 Auten 52-495 X 3,039,232 6/1962 Dunn 52--495 X FOREIGN PATENTS 1,062,948 12/1953 France.

KENNETH DOWNEY, Primary Examiner. 

